This invention relates to blind fasteners of the type that can be installed entirely from one side of a structure and more particularly to a blind fastener that is liquid tight on installation even though the screw attached thereto is removed. Conventional blind fasteners have an internal screw thread that facilitates the upsetting action of a body portion to firmly secure such fastener to a plate structure or member which screw threads are also used to fasten a separate component of a product to such plate structure by means of a removable screw. Such blind fasteners are used in those cases where it is not convenient nor practical to drill and tap the plate structure to receive a screw.
The blind fasteners heretofore used consisted of various designs wherein fastener had a tubular or cylindrical body with a head on an upper portion that was slotted and a lower body portion that was threaded. In the process of securing such fasteners to the plate structure, the upper slotted body portion would be deformed or folded outwardly thereby presenting a flanged and deformed portion which would secure the fastener to the plate structure with the head on one side and the deformed flanged portion on the other side. In this deformation process of the tubular body, the slotted portion would provide openings in the upper tubular body portion which would permit the passage of fluid from one side of the plate structure to the other side. In addition the central threaded bore of the fastener would also provide for the passage of fluids upon its removal. The present invention provides a movable sleeve that cooperates with the tubular body to seal the blind fastener from the passage of fluids in all instances of use.